The invention relates to the construction of concrete walls. More particularly, it relates to the construction of multi-layer concrete walls having a layer of concrete and a layer of insulation.
Over the last thirty years, as fuel prices have increased, it has become more and more important to develop concrete wall systems with sufficient insulation characteristics. Many of the previous methods tried have been unsatisfactory. For example, some of the original attempts to build insulated concrete walls used sheets of rigid foam that were held to the surface of the concrete by construction adhesives. These sheets were time-consuming and difficult to attach, since they required a user to apply a liquid adhesive on the back of the panel, then hold it up against the wall, pressing it against the wall until it adhered firmly and the adhesive set.
To avoid these problems, other manufacturers devised insulated concrete wall systems that used mechanical fasteners to hold the foam against the wall. The drawbacks of this system were that the mechanical fasteners abutted the foam panels themselves and were attached to the concrete wall itself. As a result, a substantial force had to be applied to the fastener to get it to grip the concrete wall. If the fastener tilted to one side, or wandered, it would shred the foam paneling and leave a gap where air, moisture or water vapor could escape. In addition, if the installer pressed too hard on the fastener, it could penetrate the foam completely, rather than stop just below the surface of the foam. If the fastener was driven with too light a touch, it would protrude outward from the foam paneling and leave a xe2x80x9clumpxe2x80x9d against which subsequently attached wall coverings, such as gypsum board, would not rest smoothly.
In an attempt to eliminate some of these problems, some tried to place large washers under the heads of the fasteners to more evenly distribute the load against the foam paneling. While this seemed to reduce the damage initially, many applicators found they often drilled too deeply, causing the washers and strips to pucker and buckle outward away from the foam paneling as the center portion of the strips and washers were pulled into the outer layers of the foam. Further complicating these efforts was the need to simultaneously (1) hold the wall board up against the concrete wall, (2) locate the proper position to install the fastener, (3) position the washer, (4) insert the fastener through the washer, and (5) drive the fastener into the wall while simultaneously holding the automatic fastener driving machine, the fastener, the washer, and the paneling in the proper orientation.
As a further complication, most insulated concrete wall systems apply foam paneling to the inside wall surface and must be subsequently xe2x80x9cfinishedxe2x80x9d with an inner layer of wallboard, such as gypsum board, which can be taped and painted, or can be covered with wall xe2x80x9cpaperxe2x80x9d or similar materials. Wallboard is typically attached to the concrete wall by attaching furring strips to the wall itself and filling the gaps between the strips with rigid foam sheet trimmed especially to fill the gaps and then attaching the wall board to the furring strips.
In addition, it is often necessary to attach a vapor barrier to the outer surface of the foam paneling to block vapor migration through the semi-permeable foam paneling and into the wallboard. This too requires the separate and independent steps of cutting a sheet of vapor barrier, unfolding it, raising it (typically with the assistance of at least two people, locating a desired attachment point through the vapor barrier, and attaching the vapor barrier with a series of fasteners to the foam paneling. Due to it floppy nature, it is virtually impossible to use an adhesive to attach the vapor barrier to the foam paneling directly, once the paneling has been installed.
All the above points to one major problem: the construction of insulated wall systems, whether interior or exterior, is a time consuming and labor intensive process. It is one of the purposes of this invention to reduce the time and labor involved in making insulated wall systems.
In accordance with a first embodiment of the invention, an insulated wall system is provided that includes a concrete wall, an insulated layer fixed to the concrete wall and comprising a plurality of insulated panels disposed adjacent to each other, each of the panels comprising a core of rigid foam, the foam having at least two reinforcing strips extending substantially the entire length of the panel, and a plurality of fasteners to retain the insulated panels to the concrete wall, wherein the fasteners have a shank, and the shank extends through the insulated panel into the wall where it is anchored. It may also include a wallboard layer fixed to the reinforcing strips of the insulated layer. A first reinforcing layer may be bonded to a first planar surface of the core of its corresponding panel and is disposed between the wallboard and the core. Each of the insulated panels of the wall system may include a second reinforcing layer bonded to a second planar surface of the core that opposes the first planar surface and is disposed between the concrete wall and the core. Each of two adjacent and substantially abutting panels may have a first reinforcing layer that extends substantially to the edge of two substantially abutting edges of the two substantially abutting panels, respectively, and may further include a self-adhesive plastic strip that bridges a joint defined by two closely adjacent edges of two adjacent insulated panels that is fixed to adjacent first reinforcing layers to join the two first reinforcing layers and form a water-resistant joint therebetween. The wall system may further include a second reinforcing layer disposed between the insulating layer and the concrete wall and fixed to the surface of the insulating layer. The at least two reinforcing strips of each panel comprising the insulating layer may be substantially parallel to each other and to two opposing edges of each of the panels, and further the plurality of fasteners may extend from an outer surface of the panels, through the first reinforcing layer, then through the reinforcing strips, and then through the core and then into the concrete wall where the plurality of fasteners are anchored. The wallboard layer may include a plurality of wallboards, and each of the wallboards may have substantially the same length and width as the insulated panels of the insulated layer. The plurality of wallboards may be fixed to the strips of the insulated panels such that each of the plurality of wallboards is attached to more than one insulated panel and each of the insulated panels is attached to more than one wallboard. A first lateral edge of a first of the plurality of wall boards may be fastened to one of the at least two reinforcing strips of a first insulated panel by a first plurality of second fasteners that extend through the first lateral edge and thence through the one of the at least two reinforcing strips of the first insulated panel and thence into the core of the first insulated panel. A second lateral edge of the first of the plurality of wallboards may be substantially parallel to the first lateral edge and be fastened to a corresponding one of the at least two reinforcing strips of a second insulated panel by a second plurality of second fasteners that extend through the second lateral edge and through the one of the at least two reinforcing strips of the second insulated panel and thence into the core of the second insulated panel.
In accordance with a second embodiment of the invention, a method of making an insulated wall system that includes a planar concrete wall having an insulated panel facing surface, an insulated layer comprising a plurality of planar insulated panels wherein each of the panels has a substantially planar wall-facing inner surface and an opposing and substantially planar outer surface that faces away from the wall and further wherein each of the panels comprises a core of rigid foam having at least two reinforcing strips extending substantially the entire length of the panel, and a plurality of fasteners that retain the insulated panels to the concrete wall is provided, where the method includes the steps of forming the concrete wall, orienting each of the plurality insulated panels with respect to the wall such that they abut each other at opposing lateral edges of each of the insulated panels and contact the wall, fastening each of the plurality of insulated panels to the wall with the plurality of fasteners such that the inner surfaces of the plurality of insulated panels are parallel to the insulated panel facing surface defined by the concrete wall, such that an inner plane defined by the wall facing surfaces of the plurality of insulated panels is parallel to the panel facing surface defined by the concrete wall, such that the wall facing surfaces of the plurality of insulated panels are substantially coplanar with each other, and such that a plane defined by the outer surfaces of the plurality of insulated panels are substantially coplanar. The wall system may further include a plurality of wallboards having a substantially planar inner panel facing surface and a substantially planar opposing facing outer surface, and a second plurality of fasteners that retain the plurality of wallboards to the plurality of insulated panels, where the method further includes the steps of orienting each of the plurality of wallboards with respect to the wall such that they abut each other at opposing lateral edges of each of the plurality of wallboard and contact the plurality of insulated panels, and fastening the plurality of wallboards to the plurality of insulated panels with the second plurality of fasteners. The step of fastening may include the steps of driving the plurality of fasteners through the at least two reinforcing strips, driving the plurality of fasteners through the cores of the plurality of insulated panels, and embedding a shank of each of the plurality of drive fasteners into the concrete wall. Each of the insulated panels may include a first reinforcing layer fixed to the outer surface of its respective panel wherein the first reinforcing layer extends across a top surface of one of the at least two reinforcing strips. The method may further include the steps of driving the plurality of fasteners through the first reinforcing layer prior to the step of driving the plurality of fasteners through the at least two reinforcing strips, and the step of compressing the first reinforcing layer between the fastener and the at least two reinforcing strips. The step of fastening the plurality of wallboards to the plurality of insulated panels may include the step of driving the second plurality of fasteners through the at least two reinforcing strips to a depth that does not cause the second plurality of fasteners to contact the outer surface of the concrete wall. The method may also include the step of driving the plurality of fasteners through the at least two reinforcing strips and into the concrete wall.